1. Field of the Invention
This invention relates generally to locks and in particular to a lock utilizing a line or cable.
2. Description of the Prior Art
Locking devices having an opening into which a cable is inserted and which grip the cable to prevent retraction from the device in the direction opposite its insertion are known in the art. Such locking devices have generally used a wedging action to secure the cable within the device.
One type of locking device are conical locks. Conical locks generally use three balls carried by a retainer within a conical shell. A cable may be inserted through the balls and retraction of the cable from the device is thereafter prevented by the squeezing of the balls onto the cable as they are wedged by the conical shell. Locks of this type are shown in, for example, U.S. Pat. No. 3,994,521.
Such locks prevent the direct retraction of a cable locked therein. However, since in most uses the cable involved has spirally wound strands, releasing the locking device by twisting it around the cable is a major problem which has been recognized in the prior art. The cone lock disclosed in U.S. Pat. No. 3,994,521 uses a conical tapered opening which is formed into a generally triangular shape, which shape, though aiding in preventing rotation of the balls and thus twisting of the cable within the locking device, is difficult and expensive to manufacture.
Further, since the balls of prior cone locks are completely retained in a unitary retainer, the locks can be picked by manipulation solely of the retainer (i.e. by moving it away from the cone taper).
The present invention is directed toward overcoming one or more of the problems as set forth above.